In the conventional approach to FM receivers typically one utilizes one separate electrical network for each function to be performed such as amplification, frequency mixing, frequency demodulation, etc. In the present invention, FM receivers include one or a small number of electrical networks, such as two terminal negative admittance networks and three-terminal negative admittance networks which perform multiple functions to form complete FM-receivers. The various functions performed simultaneously by the electrical networks are primarily based on particular features of the non-linear negative admittance of the networks.
In other U.S. patent applications, Ser. No. 725,999, entitled "Two-terminal negative admittance networks" and Ser. No. 725,998, entitled "Three-terminal negative admittance network", both filed on Apr. 22, 1985 by the inventor of the present application, (now U.S. Pat. No. 4,625,186 issued Nov. 25, 1986 and No. 4,660,001 issued Apr. 21, 1987, respectively) novel electrical networks comprising transistors are disclosed having two or three terminals and exhibiting a negative admittance.
It is also noted that another U.S. patent application Ser. No. 06/851,552 by the present inventor is filed concurrently with the present application and is directed to FM receivers using two-terminal negative admittance networks.
Although the disclosures of the above referenced applications are incorporated in the disclosure of the present application, it is felt that the present invention would be more readily understood, if brief descriptions of two-terminal and three-terminal negative admittance networks and FM receivers using two-terminal negative admittance network are included in this disclosure.